1. Field of the Invention
The present invention relates to a structure for mounting an intank type fuel pump in particular in a motorcycle.
2. Description of the Related Art
In a fuel tank of a motorcycle, what is called an intank type fuel pump is disposed in a fuel tank. In that case, an opening portion from which the fuel pump is put is provided in a proper place of the fuel tank, and the fuel pump is supported via a stay or the like by utilizing a ceiling portion or a bottom portion of the fuel tank. For example, in an intank type fuel pump device described in Patent Document 1, a fuel pump is mounted in a bottom portion of a fuel tank.
Further, in a concrete mounting structure of a fuel pump, a supporting member supporting the fuel pump and a flange (seal portion) closing an opening portion of the fuel tank are unified. In that case, though a fuel pump unit is inserted from the opening portion provided in a bottom portion of the fuel tank, the supporting member of the fuel pump is constituted in a flange shape, and a seal member such as a gasket or an O-ring is inserted into the flange portion.
Further, in mounting a fuel pump unit on a fuel tank, mounting is performed by tightening of a bolt or the like (including mason jar method, cam-lock method or the like), and in view of workability, a supporting member is disposed on an outer surface of the fuel tank.    [Patent Document 1] Japanese Laid-open Patent Publication No. 2002-303220
In the above-described structure in which the supporting member of the fuel pump and the flange are unified, as a result that excessive acceleration is generated, such as when a vehicle jumps in particular, a substantial load works around the flange portion into which a seal member is inserted. As for what is called an off-road type in particular, a height of jump is quite high and acceleration generated in that occasion is quite large.
Further, when the fuel pump is mounted in a ceiling portion of the fuel tank by bolt tightening, a height of the fuel pump unit is required to be set individually in order to reduce a fuel remaining amount.
Further, as for a fuel tank made of synthetic resin in particular, a distance (length) from a ceiling portion to a bottom portion of the fuel tank sometimes changes due to deformation called swelling, and it leads to a change of a dead remaining amount of fuel.